In automotive construction, in order to save weight as well as replace expensive metals with more economical alternatives, there has long been the desire to make electrical cables from light metals, such as aluminum, for example, and their alloys. However, when these cables come into electrical contact with a contact element, which are in particular in motor vehicles subjected to dynamic stress over a long period of many years, there are problems in maintaining the contact. One cause of such problems is the cold-flow tendency of the material, i.e., the tendency of light metals, such as aluminum, to relieve mechanical stresses in the structure even at low temperatures. Another cause is an oxide layer that is present primarily with aluminum alloys on the surface of the aluminum alloy. A further cause is the risk of electrochemical corrosion in the connecting area of the light metal strands and the contact elements in the presence of electrolytes. Therefore, there has long been a desire to provide a lasting consistent contact between light metal strands and contact elements even under the circumstances described above.
DE 10 2008 031 588 A1 discloses using ultrasound welding as a technology for joining aluminum strands. With this method, a certain ratio must be maintained between the welding width and the welding height to obtain a sufficient joining quality. In particular, with large conductor diameters from approximately 50 mm2, the required welding width quickly exceeds the actually required total width of the contact element, and thus the welding becomes the determining factor of the physical size and also creates problems with respect to sealing. In automotive electrical technology, an optimally small physical size is desired.